A charge pump circuit of a liquid crystal display driver integrated circuit (LDI) is provided, which can reduce unnecessary current consumption when a load of an output node varies is provided, where, in a gradient mode of a display-on mode, in which an output node of the charge pump circuit has a maximum load, the current driving capability of a driver in the charge pump circuit is increased, and where, in a binary mode, in which the output node of the charge pump circuit has a smaller load than in the gradient mode, the current driving capability of the driver is lower, to prevent unnecessary current consumption caused by too large driving transfer transistors in the driver and to maintain boost efficiency at a proper level.